Question

13sin46.9 - 8cos34.1/cos19

Answer 1

$\frac{13Sin46,9^{0}-8Cos34,1^{0}}{Cos19^{0}}=\frac{13Sin(90^{0}-34,1^{0})-8Cos34,1^{0}}{Cos19^{0}}=\frac{13Cos34,1^{0}-8Cos34,1^{0}}{Cos19^{0}}=\frac{5Cos34,1^{0}}{Cos19^{0}}$

Может задание выглядит так :

$\frac{13Sin469^{0}-8Cos341^{0}}{Cos19^{0}}=\frac{13Sin(360^{0}+109^{0})-8Cos(360^{0}-19^{0})}{Cos19^{0}}=\frac{13Sin109^{0} -8Cos19^{0}}{Cos19^{0}}=\frac{13Sin(90^{0}+19^{0})-8Cos19^{0}}{Cos19^{0}}$$=\frac{13Cos19^{0}-8Cos19^{0} }{Cos19^{0} }=\frac{5Cos19^{0}}{Cos19^{0} }=5$